test de cisaillement à la pelle

CONT: Le test de la pelle consiste à isoler une tranche du manteau neigeux de base carrée (la largeur est celle de la pelle, soit une trentaine de centimètres en moyenne), puis à la tirer vers soi ou à la charger pour détecter la présence de plan(s) de glissement potentiel(s).
CONT: Le test de cisaillement à la pelle n'a pas donné de résultats définitifs. [Exemple entériné par le Comité d'uniformisation de la terminologie des bulletins d'avalanche.]
OBS: [Ce test n'est] pas à proprement parler un test de stabilité.

CONT: The shovel shear test provides information about the location where the snow could fail in shear. It is best applied for identification of buried weak layers and does not usually produce useful results in layers close to the snow surface. Soft snow near the surface is better tested with the tilt board and the shear frame or an improvised version of this tilt test.
CONT: Shovel Shear Test. This test can be done on a flat or on a slope. With good technique, the location of weak layers, even thin weak layers, can be found. First dig a hole or pit in the snow. The vertical wall of the pit should be straight up and down, and smooth. Make a mark on the uphill portion of one corner of your pit with your shovel blade. This will mark the boundaries of your column, which should be roughly 30 cm by 30 cm or 12 inches square. (A) Now, cut both sides using a snow saw or your ski, all the way to the floor of the pit making sure that the cuts are straight. (B) The back of the column should only be cut as deep as your shovel blade is long, so measure with your shovel blade (C) and then cut the back. (D) Next, insert your shovel, blade down, in the back cut of the column and pull gently and evenly forward being careful not to lever your shovel handle. (E) Examine the shear layer where the block failed. (F) The force applied to the shovel that causes a weak layer to shear from the layers surrounding it can be rated as follows: Very easy ... Easy ... Moderate ... Hard ...
CONT: The results of the shovel shear test were inconclusive. [Example approved by the Avalanche Bulletin Terminology Standardization Committee.]